textproduct: Albany

WHAT HAS CHANGED

Heat Advisory continues for the rest of today and tomorrow for mid Hudson Valley and NW CT, but no additional zones added into the Advisory at this time.

Latest SPC Convective Outlook keeps marginal risk south of the area for Friday, although it's rather close. With enough shear and instability in place, thunderstorms will isolated wind damage can't be ruled out for Friday for southern areas.

KEY MESSAGES

1) Scattered to numerous showers and thunderstorms are expected through this evening and again on Friday, bringing the potential for locally heavy rain and isolated damaging wind gusts.

2) The combination of warm temperatures and very humid conditions will continue into Friday, which will result in a risk for heat-related impacts, especially in eastern Ulster, western Dutchess and southern Litchfield CT.

DISCUSSION

KEY MESSAGE 1...

Our region remains in a warm and very humid air mass. This morning's 12z KALY sounding showed a PWAT of 1.97" and dewpoints in valley areas are already in the low 70s. A slow moving boundary is located well west of the area towards the Great Lakes. Meanwhile, a strong Bermuda high is located off the eastern seaboard. As a result, there is a warm and muggy southerly flow in place over the region.

Despite limited large-scale forcing, scattered showers have already been developing across the region. Most of this activity has been fairly shallow and there hasn't been much lightning activity in our area just yet. SPC Mesoanalysis shows rather poor mid-level lapse rates thanks to the warm and humid air mass in place, with values around 5.5 deg C/km. Still, the combination of warm temperatures and humid conditions is allowing for MLCAPE values to exceed 1000 J/kg for much of the area. There is some shear in place, with 0-6 km bulk shear around 30 kts, although most of this is thanks to stronger winds within the 3-6 km layer.

While showers and some thunderstorms will likely continue to develop within the daytime heating, they look to be fairly short-lived, as the limited forcing and weak lapse rates will prevent storms from getting too tall. While the shear would suggest some storms could potentially organize, it will probably be fairly isolated, as most storms won't get tall enough. Can't rule out some isolated strong wind gusts due to collapsing storms, but the threat for wind damage looks fairly isolated at this time. With the high PWATs, heavy downpours can be expected with any shower or thunderstorm. Soils remains fairly wet across the region, so the threat for isolated flash flooding remains in place. Urban and poor drainage areas would be more susceptible to flooding today with the showers and thunderstorm activity, but any area that seeing repeated storms could be at risk.

Through this evening, scattered to numerous storms will continue but will start to dissipate after the loss of daytime heating after sunset.

Additional showers and thunderstorms will develop again on Friday. The overall pattern will stay fairly similar with our region within a warm and humid air mass ahead of a slow moving boundary with weak overall forcing and poor lapse rates aloft. Can't rule out an isolated strong wind gusts, especially for southern areas on Friday, as 0-6 km bulk shear will be strongest for southern areas. Some of the AI/ML guidance suggests southern parts of our area southward into the mid Atlantic may be at risk for some wind damage on Friday. It will remain very humid with high moisture levels, so isolated flash flooding will also continue to be a threat if areas see repeated storms.

Some convection is also possible again on Saturday, mainly during the afternoon and evening hours. Flooding downpours will continue to be a threat thanks to continued high dewpoints/PWATs, although there may be less of a concern for severe winds on Saturday. With the upper level disturbance a little closer, there may be more coverage of showers and thunderstorms on Saturday, especially for northern areas, although this is still somewhat uncertain at this time.

KEY MESSAGE 2...

With dewpoints in the 70s, heat index values have reached Heat Advisory criteria in the mid Hudson Valley already today. Heat Advisory remains in effect for Eastern Ulster, Western Dutchess and Southern Litchfield County for the rest of today and tomorrow through 8 PM. Heat Index values may reach the mid to upper 90s in these areas through this evening and again on Friday thanks to very dewpoints (lower to middle 70s) and highs in the mid 80s to low 90s. This will lead to an increased risk of heat-related illnesses. Even outside of the Advisory area, high dewpoints and warm temps could be hazardous, so everyone is encouraged to practice heat safety and take breaks in the shade and drink plenty of water. Similar temps/dewpoints will be in place again Friday. Dewpoints may be slightly lower by Saturday, which may help avoid needing additional heat headlines, although there will be a more noticeable drop in dewpoints by Sunday.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

Through 00z/Sat...Showers and thunderstorms will diminish over the next few hours with partial clearing tonight. Some MVFR cigs/vsbys within any lingering showers will primarily impact KALB and possibly KPSF at the start of the TAF period. Thereafter, following all sites seeing rain today and continued high dewpoints, fog will be possible at all sites tonight with LIFR/IFR vsbys possible. Any fog lifts by around 12z/Fri with the return to VFR conditions. While isolated to widely scattered showers and thunderstorms are possible again tomorrow afternoon, confidence was not high enough on timing or location of any storms to include in this TAF update.

Light to calm winds tonight will become west to southwesterly 5-10 kt Friday.

Outlook...

Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: High Operational Impact. Likely SHRA...TSRA. Saturday Night: Low Operational Impact. Slight Chance of SHRA...TSRA. Sunday: Low Operational Impact. Breezy. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Monday: Moderate Operational Impact. Chance of SHRA...TSRA. Monday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Tuesday: High Operational Impact. Likely SHRA...TSRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...Heat Advisory until 8 PM EDT Friday for CTZ013. NY...Heat Advisory until 8 PM EDT Friday for NYZ064-065. MA...None. VT...None.